How do i set up and ipad for my children using my Itunes account without synching my data from my Iphone? (contacts, calendar, etc

When you sync the devices to itunes, (I'm assuming that's what you mean), you can manually manage what content syncs to each device.

Syncing multiple devices with one computer

http://support.apple.com/kb/HT1495

It's easy enough to do. You can share one Apple ID and have your own content on each iPad. You do not have to have the same apps, music, books and so on. Set up the iPad with your Apple ID for purchases. If you want the kids to have their own iCloud accounts so that they can FaceTime and Message you can do that as well. However you do not have to setup additional Apple ID's in order to do that, it just makes it a little easier,

Anyway, after you set up their iPad - when you go so to sync your devices, you can set your sync preferences for each device any way that you like. Using apps as an example ... This is how you can select the unique content for you own device. You can do this in every tab in iTunes .... Apps, music, photos, movies, books, etc.

Connect the iPad to the PC and launch iTunes.

Click on the iPad name on the left side under devices.

Click on the Apps Tab on the right.

Click on all of the apps in the apps list that you want to sync to your iPad..

Click on the Sync Apps Heading.

Click on Apply in the lower right corner of iTunes

In the Info tab of iTunes, just don't sync your contacts or calendar to the kids iPad.

This will be helpful.

iOS: Syncing with iTunes

Apparently you turned on iCloud on their iPad. You can turn off Notes, calendars and contacts and whatever else you dont want to sync to their device in iCloud on the kids iPad and then your content will not sync to their device. You can also setup an iCloud account for them and then delete your iCloud account from their iPad.